Signal source localization is an important signal processing function in a wide variety of different types of systems. For example, networks of sound sensors are often used to locate and track the source of an acoustic signal associated with a sound event in applications such as security and surveillance. In such arrangements, a signal in the form of a sound wave from a sound source is typically sampled at each of the sensors, and an algorithm is applied to the resulting samples in order to estimate the location of the source based on differences in the arrival times of the sound wave at each of the sensors.
Conventional arrangements of this type are problematic, however, in that each of the sensors of the sensor network is generally required to operate at a sampling rate that is at or above the Nyquist rate, where the Nyquist rate denotes the minimum sampling rate required to avoid aliasing, which is twice the highest frequency of the signal being sampled. Time-domain samples of the sound wave from each of the sensors of the sensor network are applied to a processing device that implements the above-noted signal source localization algorithm. Thus, in order to achieve a sufficiently accurate localization result, not only is the use of high rate sampling required at each of the sensors, but those samples must be reliably transmitted to the processing device at a similarly high rate. The sampling and transmission operations therefore typically involve the use of significant hardware resources, which unduly increases the cost, complexity and power consumption of the sensors. Similar problems exist in other types of signal source localization applications.
Accordingly, there exists a need for improved signal source localization techniques, which can derive accurate localization results from a sensor network without requiring that all of the sensors of the network operate at a high sampling rate. Such techniques would ideally provide a significant reduction in the cost, complexity and power consumption of the sensors of the sensor network, without adversely impacting the desired accuracy of the signal source localization result.